Mullard
Semiconductor Type Nomenclature

All new Mullard semiconductor devices are registered internationally with 
Pro-Electron and have type numbers according to the following code, based 
on the Pro-Electron type nomenclature system for semiconductor devices.

The type number of a semiconductor device intended primarily for use in 
consumer applications (radio and television receivers, audio amplifiers, 
tape recorders, domestic appliances, etc.) consists of two letters 
followed by three figures.

The first letter indicates the semiconductor material used:

        A        germanium
        B        silicon

The second letter indicates the general application or construction of 
the device:

        A        detector diode
        C        transistor for a.f. applications (not power types)
        D        power transistor for a.f. applications
        F        transistor for r.f. applications (not power types)
        T        power thyristor (controlled rectifier)
        U        power transistor for switching applications
        Y        rectifier diode. booster diode

The group of three figures is a serial number indicating a particular 
design or development.

Examples:

        AA119    Germanium diode for use as a detector
        SF167    Silicon transistor for r.f. applications


OLD SYSTEM

Earlier semiconductor devices have type numbers consisting of two letters 
followed by two or three figures.

The first letter is 'O', denoting a semiconductor device. The second 
letter indicates the general class of device:

        A        diode or rectifier
        C        transistor

The group of figures is a serial number denoting a particular design or 
development.

Examples:

        OA91     Semiconductor diode
        OC170    Transistor

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